National Semiconductor Corporation

Randy Hsiao-Yu Lo

Boonmi Mekdhanasarn

Hem P Takiar

Abdul R Ahmed

Daniel P Tracy

Steve M Ichikawa

A lead frame having protection against electrostatic discharge is disclosed. The lead frame having protection against electrostatic discharge includes a multiplicity of leads and an electrostatic discharge protection device. The electrostatic discharge protection device includes a conductive layer and a protection layer. The protection layer is arranged to contact a plurality of leads and is formed from an electrostatic discharge protection material, which insulates the leads from the conductive layer at voltages below a predefined threshold voltage and establishes an electrical connection between the leads and the conductive layer at voltages above the threshold voltage.

Lead frame with electrostatic discharge protection

Described is a circuit board having protection against electrostatic discharge. The board includes a plurality of interconnect traces and an electrically conductive ground plane formed on a substrate such that a gap is created between the interconnect traces and the ground plane. A resistive electrostatic discharge protection material is positioned to bridge the gaps between the ground plane and the interconnect traces, such that the electrostatic discharge protection material electrically insulates the interconnect traces from the ground plane at voltages below a predefined threshold voltage and establishes an electrical connection between the interconnect traces and the conductive plane at voltages above the threshold voltage. A process of manufacturing the circuit board includes forming interconnect traces and a ground plane such that there is a gap between the ground plane and the interconnect traces. A resistive electrostatic discharge protection material is placed in the gap between the ground plane and the traces for protection against electrostatic discharge. A package including the above described circuit board and a process of manufacturing such a package are also disclosed herein.

Electrostatic discharge protection package

A method and structure for attaching a lead frame to a heat sink are provided. In one embodiment, a layer of thermally conductive, electrically insulating epoxy is formed on a heat sink and the epoxy layer is fully cured. A thermoplastic adhesive layer is formed on the epoxy layer, and the heat sink is clamped to the lead frame such that the thermoplastic layer contacts the lead frame. The thermoplastic layer is heated to its melting point and then cooled, thereby joining the heat sink and the lead frame. In a variation, a partially cured B-stage epoxy layer is used to replace the thermoplastic layer. The B-stage epoxy layer is fully cured to connect the lead frame to the heat sink.

Structure for attaching a lead frame to a heat spreader/heat slug

A portable peripheral card for an electrical device is disclosed that has an injected molded housing package. In one aspect of the invention, the peripheral card has a printed circuit board, a female electrical connector, and a solid one-piece injected molded package, whereas the molding compound includes organic polymer fibers. The printed circuit board has electrical components mounted thereon and the female electrical connector is attached to the printed circuit board to permit communications between the electrical components on the printed circuit board and the electrical device. The solid one-piece package encapsulates the printed circuit board and the electrical components yet exposes a portion of the electrical connector to facilitate electrical connections between the printed circuit board and the electrical device. In one preferred embodiment, the organic polymer fibers includes at least one selected from the group consisting of cotton, cellulose, polyester and nylon. In another preferred embodiment, the portable peripheral card is a PCMCIA card. In another preferred embodiment, the filler includes silica and organic polymer fibers. Methods of manufacturing such peripheral cards are also disclosed.

Growing community of inventors

Campbell, CA, United States of America

Randy Hsiao-Yu Lo